Two-cycle gas engine



May 29, 1945. F. M. JONES TWO-CYCLE GAS ENGINE Filed Dec. 26, 1942 2Sheets-Sheet 1 FIG.

May 29, 1945. F. M. JONES 2,376,963

I TWO-CYCLE GAS ENGINE Filed Dec. 26, 1942 2 Shets-Sheet' 2 FIG. 2.

13 /Vl// V/ 4a- 45 63 Ill" Ii. 4 54 FIG. 3. 2| 33 4r 43 'E 4s a 42 r s348w 55 I'll I J I I v q@ I j 25 2'! 23 225 I gwum vkvb FREDERICH M.JONES Patented May 29, 1945 UNITED TWO-CYCLE GAS ENGINE Frederick M.Jones, Minneapolis, Minn assignor to U. 8. Theme Control Company, apartner-. ship composed of Joseph A. Nnmero and M.

Green Application December 26, 1942, Serial No. 470,307

2 Claims.

My invention relates to two-cycle gas engines and has for its object toprovide a gas engine of this type wherein two or more cylinders havetheir piston rods and the crank shaft extending into a common crankshaft chamber and provide double pistons and double cylinders, one partof each said piston and cylinder operating as a charging chamber.

Heretofore in two-cycle engine construction, each piston and the pistonrod and crank shaft associated with it has operated in a separate closedcylinder, and the charge of fresh gas is drawn in to the lower part ofthe cylinder as the piston moves upwardly, at the same time compressingthe charge of gas above the piston, and as the piston moves downwardlythe gas drawn into the lower part of the cylinder is compressed andpushes into the upper part of the cylinder aiding exhaust, and theoperation is repeated from firing point to firing point. It has beenfound desirable and eilicient to mount in a two-cycle engine twopistons, cylinders, and gas feeding appliances, so that as one pistongoes up the other goes down. But each piston operates in its owncylinder throughout and both draws rods of the two cylinders operatingin said single chamber.

in gas from the carburetor below the piston and 1 charges the cylinderabove the piston so that each of the units thus operates independentlyof one another.

I have discovered that greatly improved operation is possible where thefuel gas is introduced into an enlarged cylinder about the piston properas the piston moves outwardly under the force of explosion to befollowed by compression of that gas so drawn in as the piston movesinwardly, the compressed gas being' forced into the other of twocylinders. In this manner, each of the cylinders receives its fuelcharge from the piston of the other cylinder, the piston rods of eachpiston operating in a common crank chamber on a common crank andperfectly balanced opera- 1 tion and increased efficiency result.

It is a principal object of my invention, therefore, to provide atwo-cylinder two-cycle gas engine with a piston having two diiferentsizes operating in two different cylinders, the smaller piston in thesmaller cylinder being the power means and the larger portion of thepiston and larger cylinder providing intake means for delivering acharge of explosive mixture to the other power cylinder.

It is a further object of my invention to provide a two-cycletwo-cylinder gas engine having a single crank casing with crank shaftbearings at It is a further object of my invention to provide pairs-ofsuperposed cylinders for each of the two cylinder units of the two-cyclegas engine, the upper of said cylinders being of smaller diameter thanthe lower cylinder, with a power piston of considerable length operativein the smaller cylinder and a piston of greater diameter attached to thebottom of the lower cylinder and operatlng in the larger cylinder so asto provide an annular space for inlet gas about said smaller cylinder atits outward stroke, where gas will be compressed in said annular chamberupon reverse movement of the piston.

It is a further object of my invention to provide a passagewayconnecting the annular chamber about the smaller piston part with theother smaller power cylinder.

It is a further object of my invention to form the opening from thepassageway leading from the annular chamber of one cylinder to the powerchamber'of the other cylinder so that it will be completely closedby'the piston during its outer stroke until substantially the end ofsaid outer stroke, at which time the gas charge in the annular chamberof the second unit will have been very greatly compressed and will inexpansion blow into the lower part of the other power cylinder againstthe customary baflie therein, thus acting to provide a succeeding fuelchargeand at the same time scavenging the powercylinder of the remnantsof combustion gas mixture.

It is a further object of my invention to provide an exhaust passagerunning from the lower part of the chamber in each smaller or powercylinder, and to provide an inlet passage running to the upper part ofeach annular chamber with suitable check valve means therein to hold thegas within the inlet passageway and the annular chambers during the upor compression stroke of the larger piston part.

The full objects and advantages of my invention will appear inconnection with the detailed description thereof given in the appendedspecification, and the novel features by which the above-notedadvantages and valuable results are secured will be particularly pointedout in the claims.

In the drawings illustrating an application 0 my invention in one form:

Fig. 1 is a sectional elevation view of a gas engine embodying myimprovements, taken along the line of the crank shaft.

each side, all of the crank shaft and the piston Fig. 2 is a transversesectional view taken on line 2--2 of Fig. 1, and viewed in the directionof the arrows.

Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 1, andviewed in the direction of the arrows.

As illustrated the motor comprises a cylinder head casting I whichprovides cylinder wall II and I2 having integral therewith cylinderheads I3 and I4 through which extend open seats I5 and is for sparkplugs I1. and I8.

The cylinder walls I I' and I: enclose explosion chambers I9 and 20 inwhich operate pistons 2| and 22, these pistons being of substantiallength so as at all times to have the walls thereof substantially incontact with cylinder walls I I and.

I2 of explosion chambers I9 and 20.

As best shown in Fig. 3, a second cylinder block 23 is secured below thecylinder block I0 and has therein a pair of cylinder walls 25 and 26enclosing cylinder chambers 21 and 28 as clearly shown in Fig.1. Thecylinder chambers 21 and 28 are vertically concentric with cylinderchambers I9 and 20, respectively, and are of substantially larg= erdiameter. Integrally connected to the lower ends of piston; 2| and 22are short piston sec- .tions 29 and 3|! which are substantially of adiameter substantially that of chambers 21 and 28, and these pistonsoperate in said chambers, which, as clearly indicated at 3| of which,open at their bottoms into a common crank case chamber 32. It followsthat the cylinder 29 and 30 at all times seal the chambers 21 and 28from the crank case chamber 32. Further, that at the limit of theoutward stroke of the-c0mbined pistons, as for example, pistons 2| and29, Fig. 1, there is formed in the cylinder chamber 21 (or 28) anannular chamber 33 extending about the power piston 2| (or 22) andinside cylinder walls 25 (M26). j

The pistons 2| and 22 are provided with piston heads 34 and baiiles 35,see Figs. 1 and 2. Opposite the position of said baflles when the pistonis in its outward position, as is piston 2| in Fig, 1, are peni gs 31and 38 into cylinder chambers I9 and 20, respectively, which openingslead through a manifold passageway 39 in the cylinder block II) to anexhaust pipe 40 of common construcq tion.

As shown in Figs. 1 and 3, a manifold passageway 4| extends through thecylinder block 23 and opens at and 43 into the cylinder chambers 2! and28, respectively. The passageway 4| leads is at the end of powerexpansion from explosion when-the explosion gases have reached one orthe other or the openings 21 or a and the pressure within the explosioncylinder has therefore dropped, so the inrush of ga from the compressionchamber against the baflle 25 will cause the explosion chamber I! or tobe filled with inlet gas mixture and at the same time scavenge out" theremainder of the explosion gas going to the exhaust.

In a customary manner the pistons 2| and 22 are made hollow and areprovided with wrist pins 54 which are connected by piston rods II withcrank bearings 56 on a single crank shaft which has its ends 51 and ismounted in frame pieces 59 and '80 on ball bearings 6| and 62. Startermechanism indicated generally at 63 is connected with the crank end 58in a known manner. A pan 84 closes the crank case chamber 22 at itsbottom in a customary manner.

From the above it will be seen that the piston rods and crank shaft forboth cylinders of the two-cylinder engine operate in a single crank casechamber, which greatly facilitates lubrication, simplifies construction,and produces the balance of operation' which is requisite .for amultiple cylinder engine. It will be clear that while only two cylindersare shown and described herein, cylinders in any multiple of two, astour, six, eight or twelve may be employed. A customary breather, notshown, going to the crank case chamber 32 may be applied in any desiredmanner.

to a valve chamber 44 in an extension casting 45 which carries a checkvalve 46. The valve seat passageway 41 leads into an inlet passageway 48running to a carburetor of known construction, not shown.

In the cylinder block III are formed passages 49 and 50 extendingrespectively from compression chamber 28 to explosion chamber I9, andfrom compression chamber 21 to explosion chamber 20, all as clearlyshown in Figs. 1 and 2. The openings 5| and 52 from passages 49, 50 intoexplosion chambers I9 and 20, respectively, are

positioned in the respective cylinder walls II and I2 at a point justabove the point reached by the piston head 34 when the pistons 2| and 22have reached the limit of their outward stroke, as indicated in dottedlines at 53 on Fig. 1. This.

brings the respective openings 5! and 52 opposite the bailles 35 onpiston heads 34. Since the pas-3 sageways 49 and 50 extend respectivelyfrom upposite compression chambers to opposite explo-- sion chambers, itwill be apparent that the charge 1 of fresh gas will be fully compressedin the an- The advantages of my invention have appeared quite mlly fromthe foregoing specification. A primary advantage is a perfectly balancedoperation 01' a two-cylinder two cycle gas engine. This balance isproduced by reason of the fact that as one piston operating in itsdouble cylinder responds to the power explosion and simultaneously drawsin a fresh charge of gas mixture, the other piston in the secondcylinder is compressing the charge in the explosion cylinder and alsothe charge drawn in by it at the time oi the preceding explosion. Thepower stress of explosion in one cylinder is therefore to some degreecompensated by the elastic compression stresses of the other cylinder.This balance in operation gives a remarkably smooth flow of power with ahigh degree of economy for the gas'burned.

A further very great advantage which flows from that above-noted, isthat my invention admirably adapts a two-cycle principle of operation ofa gas engine to use in a multiple cylinderexplosive engine.

I claim: I

1. A two-cycle gas engine, comprising a block having formed therein apair of power cylinders, each of said cylinders being continued into anenlarged cylinder portion, said enlarged cylinder portions openingdirectly into a common crankcase chamber, an enlarged piston part insaid enlarged cylinder, a source of explosive asvaaes the enlargedpiston. and charging passageways in the block connecting the tops ofeach enlarged cylinder with the bottoms oi. opposite power cylinders,whereby explosive mixture will be drawn into an enlarged cylinder fromsaid firstnamed passageway upon outward movement oi. its enlargedpiston, and return movement of the enlarged piston will causecompression of the gas mixture about the explosion piston and thecompressed gas mixture will ilow through the charging passageway to theopposite power cylinder at termination 01 the down movement of one andthe up movement of the other piston.

2. A two-cycle gas engine, comprising a block having formed therein apair of power cylinders, each of said cylinders being continued into anenlarged cylinder portion, said enlarged cylinder severally thereintoalong a common plane at substantially the upper limit oi. the stroke oithe enlarged piston, and charging passageways in the block connectingthe tops of each enlarged cylinder with the bottoms of opposite powercylinders, an exhaust passageway having enlarged openings into thebottoms of the power cylinders, said openings being directly oppositethe openings from the said charging passageways, whereby explos'ivemixture will be drawn into an enlarged cylinder from said first-namedpassageway upon outward movement of its enlarged piston, and returnmovement of the enlarged piston will cause compression of the gasmixture about the explosion piston and the compressed gas mixture willflow through the char ing passageway to the opposite power cylinder attermination of the down movement or one and the up movement of the otherpiston, and exhaust will take place through said exhaust passageway atthe same time that the gas is entering the power cylinder from thecharging passageway and will act to scavenge the exhaust gases from saidpower cylinder.

FREDERICK M. JONES.

